solution:

a) To calculate the volume of cube of edge 1.0cm

Volume= (edge)³

=(100cm) ³

= 1cm³

To find the mass of MG atoms

Density = mass/volume

Mass of mg = 1.74g/cm³ x 1cm³

= 1.74g

To find the number of mg atoms,

Molar mass of mg = 24.31g

24.31g mg contain 6.022 x 10²³ atoms of mg

1.74g mg contain = 6.022 x 10²³mg atoms/24.31g mg x 1.74g mg

= 0.4310 x 10²³mg atoms

= 4.31 x 10²² mg atoms

B) to find the volume occupied by mg atoms

Total volume of cube = 1 cm³

Volume occupied by mg atoms

= 74% of 1cm³

=74/100 x 1cm³= 0.74cm³

To find the volume of 1 mg atom

4.31 x 10²² mg atoms occupy 0.74 cm³

1 atom will occupy 0.74cm³

1 atom will occupy = 0.74cm³/4.31 x 10²²mg atoms x 1mg atom

volume of 1 mg atom = 0.1716 x 10⁻²²cm²

Volume of 1 mg atom = 4/3 π³ in the form of sphere.

4/3πr³ = 0.1716 x 10⁻²²cm³

R³ = 0.1716 x 10⁻²²cm³x 4/3 x 7/22

R³ = 0.04095 x 10⁻²²cm³

R = 0.1599 x 10⁻⁷cm

1 = 10⁻¹⁰cm

= 0.1599 x 10⁻⁷cm

= 1pm/1 x 10⁻¹⁰cm x 0.1599 x 10-7cm

= 1.599 x 10² pm

R= 1.6 x 10²pm